Historical sketch on Immunity 513 



ments of the organ in question. Inflammation, therefore, is 

 arded by Buchner as a salutary reaction, which acts, not directly [536] 

 the exciting morbific cause, but through the mediation of the 

 specific cells of the organs. This theory of immunity led Buchner to 

 propose arsenical treatment as a remedy against microbial disease, 

 because arsenic is, of all drugs, the one capable of setting up the 

 greatest inflammatory reaction. 



Another German observer, Grawitz^, proposes a theory of acquired 



immunity, according to which a first attack of an infective disease 



sets up "the adaptation of the cells to the power of energetic 



assimilation of the fungi.'' This reinforced adaptation is transmitted 



to the descendants of the cells which have acquired it, and for 



that reason the immunity may persist for months, and even years. 



Grawitz attempted to base his views on experiments on the acquired 



immunity against the fungus of the lily of the valley, but Loeffler^ 



soon demonstrated that this thesis could not be maintained, and that 



the immunity assumed by Grawitz did not, in reality, exist. 



1^^ It will be seen that all the theories summarised above are marked 



IHk their vague character and want of precision ; this is not at all 



l^fetonishing when we take into consideration the very imperfect 



^Knowledge of the phenomena of immunity. It is evident that if we 



wish to gain a satisfactory idea of the mechanism of the resistance 



of the animal body against pathogenic micro-organisms, we must 



inform ourselves as to the modifications which take place in the 



organs and tissues at the time of the acquisition of the immunity, 



and also find out what becomes of the micro-organisms in a refractory 



animal. 



We have seen that Chauveau demonstrated that anthrax bacilli 

 when injected into the vessels of Algerian sheep disappear, but he 

 was unable to say anything as to the way in which this disappearance 

 was brought about in nature. Buchner accepted the reinforced 

 resistance of inflamed organs without being able to describe the 

 phenomena which manifest themselves during the inflammation of 

 tissues invaded by the pathogenic micro-organisms. 



Independently of these theoretical and rather speculative views 

 on immunity, there has been an addition to our scientific assets of 

 fairly exact data on the relation of certain pathogenic organisms to 

 the organs and tissues of susceptible or refractory animals. When, as 



1 Virchow'8 Archiv, 1881, Bd. lxxxiv, S. 87. 



2 Mitth. a. d. k. Gsndhisamte, Berlin, 1881, Bd. I, S. 134. 



33 



